Prelude
by Super Widget
Summary: Moriarty origin story (sort of). A prelude to a master criminal conducted by a love affair. Moriarty/OC
1. Chapter 1

_Authors Note: Just a little something that's been swimming in my brain lately. Sorry about the info dump. Will write more depending on demand and stuff. Enjoy!_

_A Treatise on the Binomial Theorem_… James watched the cursor blink at the end of his thesis header, unsatisfied with his choice of title. If anything, it was apt; a simple title for a simple paper. His lecturer had said regarding the thesis at the start of the year, "You can either write a hard subject poorly, or an easy subject well. Do whichever will earn you the most marks."

All math came easy to James. He chose a subject that would be easier for the examiners to grade and hence worth more marks. But typically, for all his complex, algebraic scrawling a more sophisticated title failed him.

His phone vibrated on the desk next to his keyboard. The name "Kathy" appeared on the screen. He had made lunch plans with her today, and even though he set the reminder on his phone, she sent him a confirmation text message anyway.

"_The usual?_" it read. He exhaled a short huff of amusement. They were only seeing each other for two months and they already had a '_usual_' eating place.

"_There in five_." he texted back before tapping CTRL S on his keyboard repeatedly.

It was shortly after two o' clock when James arrived at the café. The lunch hour rush had evidently passed and most of the available tables were littered with used napkins and empty plates. He spotted Kathy who was reading alone in the corner that was most coveted for its sofa seating.

James first met Kathy on a class night out he was forced to attend. He was never one for socialising and could never really get into college culture. It was one particular peer, one who insisted on being his friend, that urged him to do so.

"Sure you'll go for one," was the unrelenting mantra James was inflicted with until he acquiesced.

_Sure why not? _James had said to himself. _Let's give this being normal thing a whack._

Normal, however, was something that James never really got the hang of and so it wasn't long before he grew bored of his class night out. And then he met Kathy, a psychology student as it turned out - bright, nerdy and as far from normal as he was. They began conversation on their mutual distaste for nightlife and the rest as they say is history.

Kathy, as if sensing his presence, looked up from her book and flashed a smile. James smiled back and went to sit next to her. She was wearing a white blouse with black corduroy shorts, white knee-highs and clunky black shoes. Her small face was adorned by large, thick framed glasses and her fine, chocolate hair was tied up in her usual ponytail. If anything, she was a sweet girl. Initially she tried to sell herself as 'not like the other girls' unwittingly exposing her low self-esteem but James enjoyed her company and it was all he cared about. At least he cared two months ago when their relationship was fresh and exciting, but as with everything else, James was growing bored. He had scolded himself for being fussy. Making friends was hard enough when he was too different from everyone else. There was nothing wrong with Kathy, but to James the relationship felt hollow, like some sort of social obligation to appear normal. But James clung onto it for now, hoping it would improve in some way.

"How's the thesis coming?" Kathy asked cheerfully as she pecked his cheek.

"Formulae are imprinted on the inside of my eyelids," he drawled, "But it's getting there. How've you been?"

Kathy could talk for Ireland. It was only after they finished eating lunch and started eating dessert that James realised he hadn't gotten a word in since he asked the question.

"…which leads me to believe…" she paused suddenly then. Mild panic tugged at his brain as he tried to remember what it was she was talking about to begin with…something about her studies…? He glanced at her. Her expression was curious and one finger pressed firmly against a tight smile.

"What?" he stated cautiously as if he were under scrutiny.

"James," she whispered and glanced around carefully. James imitated her and concluded that no one was within ear-shot.

"What?" he said again, through a nervous half-laugh.

She bit her lip, her cheeks flushing as she took a deep breath.

"I think…" she started, but stopped and tried again, "I was wondering…have you ever killed someone?"


	2. Chapter 2

James choked on his cheesecake.

"Say that again?" he rasped, taking a drink of coffee to wash down the biscuit that lodged in his throat. Kathy faltered, her face turning red.

"Uh…" she stammered, "That didn't quite come out right."

"You just asked me-" James looked around and back and lowered his voice, "if I had _killed _someone."

Kathy hesitated and appeared to be thinking carefully.

"Yes." she stated eventually.

James couldn't tell whether this was an educated guess or whether she knew something about his past. Typical psychology students, always trying to apply text-book material to the people around them. But James had not counted on Kathy to get into his head like this and wondered what her intent was. He responded with silence, imploring her to elaborate.

"Well, I mean it's just that-" Kathy motioned awkwardly with her hands, unable to finish the sentence.

"You think I'm a killer," James responded bluntly, his eyes staring coldly.

Kathy opened her mouth to speak but nothing came out. No, she was done. She had nothing on him. James was a little surprised to find that he was disappointed. Without a word, he dropped a twenty on the table and left the café.

He had thought about ending it with Kathy before. At least now she would think that she was in the wrong, that the break-up would be her fault. No skin off his back. It was fun while it lasted.

"James!" He heard Kathy call after him as he turned onto a quiet street. She caught up, walking backwards in front of him until he stopped.

"Get out of my way," he calmly warned.

"No, hold up," she said, a new confidence in her voice, "I know you think I'm crazy but hear me out."

James shifted impatiently but let her speak. He was interested.

"I just…I just want you to know that you can be yourself around me," said Kathy with a reassurance in her tone, "And I've noticed that you're not yourself. Ever. You hide behind this socially acceptable façade constantly. But I can see pass that. I know who you really are, James, and I'm… I'm ok with that."

"And how would you know," he said quietly, "who I really am?"

She smirked with a tilt of her head and whispered, "I can spot a psychopath from across the room. Like I spotted you that night at the bar."

"And you think I've killed people."

"I've noticed that some people around you tend to die. Tragically. Accidentally."

James tried to figure out what her angle was.

"Are you worried you'll meet the same fate?" he replied, his eyes locked on hers.

"Oh I'm not afraid of you," said Kathy, "I was only wondering would you be willing to kill again?"

"Jesus, Kathy." He turned away disgusted. He knew she had few loose screws in that head of hers but he didn't expect this. He hadn't pegged her as disturbed, morbid, with a lust for killers and what they could do. He didn't need this. He was not about to be someone's pet psychopath.

"I'm in trouble, James," said Kathy, her tone melancholy, "I need your help. You're the only one I can trust."

"You think I'm a killer and you trust me?" he cried.

"With this, yes. I owe money. A lot of money. At this point my life is in danger."

_Christ, James, you sure can pick them_, he said mentally.

"I can give you money," he offered.

"No," Kathy shook her head with a tight smile, "This is a drug dealer we're talking about. Once I pay up he's going to expect me to come back for more. He expects my regular custom. I thought my bad credits would put him off me but it didn't work. I need him out of my life. Permanently."

James ran a hand over his face and sighed inwardly. At least Kathy had been right when she said she wasn't like the other girls. She was far too trusting of him knowing what she knew. Anyone else would have run a mile, but Kathy saw her position as an opportunity. It was the trust that made him wary, though. She had either deluded herself into thinking he cared that much about her or she was using him for her own gain. Both notions concerned him and he knew he had to exercise caution.

"So what do you say?" Kathy asked carefully, "About my problem? Can you fix it for me?"


	3. Chapter 3

_**Author's Note: I realise that the opening paragraph here should have been in the previous chapter but because of the POV switch I had to put it in this one so as not to confuse anybody. Also the rating went up in this chapter just FYI ;)**_

"I don't think we should see each other anymore." said James.

Kathy's face fell. _Shit! _

"What?" she whimpered, disappointment sank like a stone in her chest.

"I can't," he said, shaking his head and walking away, "I can't do this." He hailed a passing taxi.

"James, wait!" she cried, briskly following, "James!"

He hopped into the taxi and slammed the door just as she reached him. He wouldn't even look at her.

"Dammit!"

_Stupid, Kathy, stupid! _She scolded herself as the taxi drove out of sight. She pulled out her phone but stopped herself before she could call him. No. He'll come back. He's interested, he'll come back.

One agonisingly long week had passed and James had not made contact since the last time they spoke. Kathy decided to throw in the towel and try to make amends for her mistake. She stood outside the apartment building in which he was residing and buzzed his flat. An apathetic "Yo!" hissed through the static. Kathy had only been here a few times before but she recognised his roommate's voice.

"Is James home?" she spoke through the intercom.

"Yeah."

"Can you let me in?" The heavy, metal door opened with a click.

"Christ sake, Derren, you're lucky I'm not a serial killer or anything," she muttered to herself as she entered the building. James' flat was on the third floor and the door was left unlocked, presumably so that Derren's girlfriend could come and go as she pleased. As she entered she was hit with the unmistakeable stench of weed. Derren, scruffy and skinny, sat in front of the TV with one arm around a blonde girl and holding a joint in his free hand. The flat was a dive. James said that he had given up trying to keep it clean as Derren's lack of hygiene made it almost impossible.

The couple didn't so much as glance as Kathy as she crossed the living area and into the hallway towards James' room. His door was shut, nothing but silence came from the other side. She knocked.

"What?" came the blunt reply.

Kathy let herself inside. The bedroom was remarkably impeccable in comparison to the rest of the flat. James was seated at his desk with his back to the door, typing busily on his laptop.

"Hi," Kathy said meekly. James paused and visibly sighed before continuing his typing.

"I'm sorry," said Kathy as she took a step closer, "I was way out of line. I should never have put you in that position. Your past is your past and it's none of my business and I'm sorry I brought it up. I was an idiot, ok? Can we forget that this every happened and go back to the way things were?"

Kathy wrung her hands in agitation. James continued to work quietly. His silence frustrated her.

"Please, James? We're good together. And I don't make friends easily but with you everything is easy. And I know you feel the same. At the end of the day all we have is each other. I want this to happen, I want us to work."

Without a word, James shut his laptop and stepped passed her towards the door. Her heart sank.

"James, I'm sorry!" she said pleadingly, "At least talk to me."

Instead of leaving the room like she thought he would, he shut the door and stepped behind her, wrapping his arms around her body. His dark eyes stared at her through the wardrobe mirror before them. Kathy's heartbeat increased. His touch sent a warmth through her stomach but his glare chilled her to the bone.

"Are you sorry?" he murmured, his breath on her ear giving her goose bumps.

"Yes," her voice quivered as his hand ran down her side.

"It won't happen again?"

She picked up an underlying danger in his voice. He was exhibiting dominance. Good, she thought. She could work with this.

"I promise." Her last syllable was cut short by a gasp as James' hand moved up her tartan skirt and plunged beneath her underwear, his fingers meticulously working the already moistened area. James used one foot to spread her legs apart so that he had better access. This was the first time they had engaged in any sexual activity besides kissing. Given his condition, James' actions not only fascinated Kathy, but also sparked arousal in her. It was evident that he already had sexual experience and favoured the role of the dominant over the submissive judging by the way he trapped her tightly against his body while stimulating her. Through the mirror she could see him watching her, a small smile tugging at the corner of his mouth. Everything about him said control.

All thought dropped from Kathy's mind as the sensation between her thighs intensified. She wanted to cum, but every time she reached the edge James would pull her back by changing his pace. It was torment. She could feel his erection press against her lower back and the thought that he desired her drove her insane.

It only took a split second for James to drop his guard in which Kathy spun to face him, desperately undoing his jeans. He caught her by the mouth as she lunged forward, causing him to fall into a seated position on the bed. Kathy wrapped her legs around his torso and used one hand to move her thong aside to allow his erection inside her. She fell into him, stealing the dominant role from him as she trapped his wandering hands by his sides so she could concentrate on finishing. With her arousal at its peak and the strained thong stimulating her already sensitive clit, it didn't take long for her to climax. The sensation exploded inside her. The cries that escaped her throat were strangled to a whisper as her whole body tensed. A few small pelvic thrusts to extend the sensation and she was done. She collapsed forward like a rag doll, her head resting on his shoulder. For a long moment they remained in that position until James kissed her neck and she raised her head to meet his gaze. He appeared to have an amused expression on his face. Kathy, as if just realising what they had done, blushed deeply. This was their first time with each other and Kathy felt a little embarrassed having exhibited that much intimacy with him. This seemed to amuse James even more. She cleared her throat and disentangled herself from him.

"Oh," she said realising that her contractions must have caused him to finish inside her, "Sorry about the mess."

James shrugged dismissively. "It's laundry day, anyway," he said. He stepped over to the laundry basket by the wardrobe and began removing his dampened clothes.

Kathy wasn't sure what to say. Were they ok now? What was going through his mind? Did she really want to know?

"So…" she began, thinking carefully about her next few words. James glanced at her and she realised then that this was the first time she had ever seen him naked. _Wow_.

"So…?" he prompted her to finish her sentence. She decided that she didn't need to say anymore, at least not in that moment.

"You want to go again?" she asked, her stomach swirling with heat again as he approached her.

"I'll need a moment to reload," he replied mischievously.

"I don't," she said.

He smirked and they kissed deeply before starting all over again.


	4. Chapter 4

_**Author's Note: For the pedantic reader please note I am being slightly liberal with the timeline here. Moriarty is roughly in his early to mid twenties and the year is early to mid 00's. **_

They spent much of the afternoon experimenting and exploring each other. James never really believed that one could be "good at sex" per se. One could know the basics and alter known techniques based on the other person's preference. It usually took time for a couple to get to know each other intimately unless they were sexually compatible off the bat. He and Kathy however just clicked. Kathy was fun, vivacious, and James immensely enjoyed fighting her for dominance. People he had been with before were mostly passive, but Kathy was a challenge much to his delight.

They had been lying together in silence for some time now, the room growing dark with the approaching evening. Kathy had draped herself across his body, her head resting on his chest. She was exhausted and trembling from their arduous activities. Her pony-tailed hair had come loose at some point and James' fingers ran through her tresses, gently massaging her scalp, to which she moaned softly in appreciation.

"I was 11," said James unprompted.

"Hm?" Kathy responded absently.

"When I first killed someone."

Kathy looked at him lazily.

"Carl Powers." she affirmed.

A mirthless smile tugged at the corner of his mouth.

"How much do you know?" he asked, deadpan.

"As much as the obituaries do," she replied with a shrug. He gave her a look.

"Ok so after we met I might have done a little research," she said defensively, "Don't take it personally, I just have trust issues. And I like learning about people. It's what I do. People fascinate me."

"I'm more concerned about how you came to the conclusion that I had anything to do with Carl Powers' death."

Kathy, in her usual manner, spoke quickly and animatedly.

"Oh. Well I didn't at first. Well I _did _think 'huh, that's a little weird that an athletic swimmer drowned in a swimming pool'. But then I noticed that _other _people you happened to know also mysteriously died, including a secondary school teacher and your parents. Combine that with the fact that you're kind of a psychopath and it's kind of a no-brainer."

"You think I'm a psychopath?" James replied feigning offence.

Kathy propped herself up on one elbow and grinned.

"When I asked you to kill someone, you ignored me for a week and then bonked me senseless. Psychopath is definitely a theory I'm running with."

"You're oddly at ease with that," James pointed out.

Kathy shrugged.

"I have to be," she replied, "If I held my own practice I'd have to listen to everybody's dirty little secrets. I can't really afford to care about that kind of stuff lest it affect my work."

"And you're not afraid of me?" James pushed, "Of what I could do to you?"

"Oh, no," Kathy replied with a crooked smile, "You like me too much."

He did like her but it didn't mean she was the exception. _Just don't give me a reason_, thought James. There was a moment of silence between them. Kathy absently traced a finger across James' bare chest before she spoke again.

"So 11, huh?" she said solemnly, "That's quite a young age for your first murder. How did it make you feel?"

James had to think about it. It wasn't triumph, the act itself was easy. It wasn't pride when he had achieved greater things. It wasn't joy, it was something stronger than that. He had removed a burden, he had taken a life and he had gotten away with it. Almost fifteen years had passed and there was still no link between him and his crime. He was untouchable.

"Powerful," he said eventually.

Kathy gazed at him, her small grey eyes revealing something akin to coveting…lust.

"I bet," she whispered and James was struck with a familiar trepidation all over again. She was fascinating, of that there was no doubt, but he couldn't quite figure her out and that unnerved him. He learned nothing more of her during their week apart and not from lack of trying. He decided to keep her close and keep her wanting. She was clearly comfortable with who he was and he would be fooling himself into thinking that she was just a misguided young woman with a lust for bad guys. Then again, maybe this was the excuse he told himself to continue the relationship. Maybe he actually had feelings for her. He couldn't decide.

"I'm hungry," Kathy said after stomach audibly rumbled, "Wanna order pizza?"

"No," James replied and Kathy's face fell. "Go home. Clean yourself up. I'm taking you _out _for pizza."

Kathy grinned and sprung up, searching for her assorted garments that had been tossed in various directions during the throes of this evening's passions. James picked her glasses from the nightstand and waved them in front of her.

"Yes," she said as she took them, her face more familiar now as she slid them on, "These might help me find my clothes."

James threw on a pair of slacks and grabbed a towel from his wardrobe in preparation for a shower.

"So where are we going?" Kathy asked, hopping into one of her knee-highs, "Pizza Hut?"

James grimaced.

"Not a fan of salmonella," he replied, "No, somewhere a bit nicer. I suggest you wear your best."

"Oooh, somewhere fancy?"

"You'll see," he teased, planting a kiss on her mouth.

When she was fully dressed he saw her to the door.

"Text me when you're ready and I'll come meet you," he said.

"Kay," she replied, a smitten grin on her face, and she disappeared down the corridor.

James shut the door behind her and turned to find Derren giving him a thumbs up and a nod of approval. He discretely rolled his eyes.

"I'm taking a shower," he said, "Don't run any water while I'm in it."

"Oh, Jimbo, before you head," Derren called after him, "It's the missus' birthday this week, we were thinking of throwing a party here. It's just a small thing, no biggie, but if you're here you can invite your own posse or whatever. We're cool with that."

"Right," James nodded tersely.

_God, give me patience_, he pleaded silently as he trod off to the shower.


End file.
